Hemorrhagic stroke accounts for 20% of the annual stroke population. Hemorrhagic stroke often occurs due to rupture of an aneurysm, causing bleeding into the brain tissue and resultant infarction of brain tissue. This can cause immediate death, as well as several well-known neurological defects such as paralysis, loss of sight, hearing or balance. Even if aneurysms in the brain do not rupture, they can cause severe neurological symptoms. Aneurysms may be filled with occlusive material, such as embolic coils, flow modifiers, stents or embolic polymers (ethylene vinyl alcohol, cyanoacrylate, etc.), to prevent rupture and alleviate neurological symptoms. This treatment is promising for many aneurysm in the cerebral vasculature. However, the cerebral vasculature includes many branches and bifurcations where an inlet artery branches into two outlet arteries. Large necked aneurysms (greater than 4 mm, with dome to neck ratios of greater than two) often form at these bifurcations, and the location and openings of these aneurysms often make it difficult to keep occlusive material, once placed in the aneurysm, from falling out of the aneurysm and into the arteries, thus blocking the outlet arteries. This can lead to an embolic stroke, which is just as severe as the hemorrhagic stroke the therapy is intended to prevent.